更新 app-manual-cpp.md

d37e1b89 · 宋海霞 · 0f163e05 · d37e1b89
--- a/app-manual-cpp.md
+++ b/app-manual-cpp.md
@@ -116,7 +116,7 @@


 ```c
-#include "iostream"
+#include <iostream>
 using namespace std;
 int main(int argc, char* argv[])
 {